Ice borers



United States Patent O 6 claims. (El. 175-1s) The present invention relates to means for boring in ice, in particular means of the kind comprising a spoonshaped or partly spherical boring member attached to a rod with a crank or similar means for rotation of the borer.

Such boring means have an edge along about half of the curved rim of the boring member and they are satisfactory in operation insofar as the spoon-shaped boring member is guided correctly along the internal Wall of the hole, in such a manner that the edge will be in correct cutting position when the boring member is rotated.

These known means for boring in ice are inexpensive in manufacture compared with other types of boring members constructed in accordance with the spiral boring principle, for example the boring member described in Norwegian Patent No. 76,299, but the known spoonshaped boring members also exhibit a few rather serious disadvantages. Due to the round or continuously curved edge, the known boring members are difficult to start Le. the boring member will easily slip to one side during the first rotations so that it is very nearly impossible to locate the hole exactly at the point where it is desired. This is of particular importance if a previously bored hole which has frozen is to be opened again. It is then necessary to start the boring so that the new hole is in alignment with that part of the old hole which is not yet frozen, .and this operation is as mentioned above very diflicult. Another and still more serious disadvantage is that the previously mentioned cooperation between the guiding of the spoon-shaped boring member and the cutting position of the edge of the known designs of boring means is so critcial that the quality and the bite of the boring members will be very variable, and experience has shown that new boring members with an apparently sharp and excellent edge thus do not cut at all if the position of the edge is slightly incorrect in relation to the convex side of the boring member. The reason is that the convex side of the spoon-shaped boring member will be guided along the wall of the hole and this stable guidance together with curved shape of the edge will prevent the edge from coming into suiiiciently close contact with the ice, and the result will be an inferior bite Further the continuously curved edge is very difficult to grind and sharpen accurately in a particular predetermined angle to the rest of the boring member during the manufacture of same, and the abovementioned unsatisfactory cooperation between the edge and guide members will frequently be the result.

The above disadvantages concern manufacture and new means for boring in ice but the above disadvantages are still more pronounced when it is necessary in the future to sharpen the edge after it has been blunted through repeated use.

One object of the invention is to provide means for boring in ice, of the kind described, which is easily started exactly at the desired point.

Another object of the invention is to provide means for boring in ice in which the cooperation between the guidance of the convex rear side of the boring member and the cutting edge is such that a better control of the feeding is obtained than in the case of known embodiments of boring members.

Patented Mar. 30, 1965 "ice Still another object of the invention is to provide means for boring in ice which easily may be manufactured with a uniform quality so that each customer may be surer of getting a boring member which has the correct bite The final object of the invention is to provide means for boring in ice which in a simple manner may be resharpened after becoming dull.

,Further objects and advantages of the present invention will be apparent from the following description, reference being made to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

In the drawings:

FIG. 1 is a side view of a boring member constructed in accordance with the invention.

FIG. 2 is a top view of the boring member of FIG. l, and

FIG. 3 is a view corresponding to FIG. l but showing the boring member attached to a rod for rotation and with the boring member ready for boring a hole in the ice.

Referring now to FIGS. 1 and 2, the boring member is generally spoon-shaped or shaped as a hollow member, referred to as 1. This boring member has a sharpened cutting edge along a part of the lower rim comprising the lower boring end or tip and leading edge as shown at the right in FIGS. l and 3 of the drawing, which, on previously known embodiments for ice boring means of this kind the edge continues as a uniformly curved rim with the same curvature as the edge. In accordance with the invention the rim 3 is, however, located on an arc having a center of curvature located outside the outline of the boring member, with a section removed as compared with the known embodiments. The concave rim section 3 of the trailing edge of the boring member 1 defines a relatively large indent or recess 4 in the trailing edge opposite to the cutting edge along the leading edge of the boring member.

The rim section 3 which is not provided with a sharpened cutting edge and the adjoining side faces will then, as experiments have shown, enable far greater cutting speeds with less pressure on the boring member.

The cutting edge of the boring member 1 is located generally along an arc the center of curvature of which is located inside the outline or peripheral dimensions of the boring member 1 and is formed by straight edge sections 2, 2', 2", 2"', the linear edges being simple to grind and sharpen during the manufacture of the boring member, and the straight sections are also simpler to resharpen after use. Another advantage in addition to the advantages mentioned above is that two of the linear edge sec-tions Z and 2 are joined at a point 5, which will be the lower point when the borer is in operative position. This is indicated on FIG. 3 in which the reference number 6 refers to the surface of the ice in contact with the point 5. A rod 7 provided with a crank (not shown) is attached to the boring member 1 by means of bolts or rivets 8 and the rod 7 is as shown slightly inclined. This is, however, of no importance for the start of the boring operation as the point 5 will bite satisfactorily in the ice within a wide range of inclined positions of the rod 7. At the start of the boring operation the boring member 1 will then rotate on the point 5 and approximately with the line 9 on FIG. 1 as axis of rotation. The posi-tion of this axis will of course depend on how the rod 7 is held during the boring operation and also on the position of the rod, but these conditions have proved to be of hardly any practical value for the result. At the start of the boring operation the edge section 2 will cut the ice while the edge section 2 will trail and act as a guide during the first part of the boring operation. The convex surface 10 of the boring member 1 will, however, fairly soon during the boring operation start to follow the wall of the hole, and instead of rotating about the axis 9 the boring member will start to rotate about a point which fairly closely will correspond to the center of curvature of the external convex surface 10 of the boring member 1. Itfwill be seen that the edge section 2 which at the start of the boring operation (FIG. 3) was trailing, seen in the direction of rotation now (FIG. 2) also will take part in the cutting of the ice when the boring member is moving along the wall of they hole in the direction indicated by the arrow 11.

It is a particular advantage to let the axis 12 of the rod 7 (FIG. 1) extend at a distance from the point 5 and not through same because the rod will then have a more correct position during the rest of the boring with the complete edge in action and because the exact positioning of the rod 7 is immaterial at the start of the boring, as explained above.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other formsmay be adapted, all comi ing within the scope of the claims which follow.

I claim: l v .v

1. A devicefor boring in ice comprising a generally spoon-shaped boring member and means for effecting its rotation, said boring member having a' curved trailing edge and a sharpened leading edge and boring end pro-v viding a cutting edge on said boring" member, said cuting edge being comprised of. a plurality of straight cutting edge sections arranged in series with adjacent straight edge sections meeting at .an angle withv respect to each other. Y

2. A devicev for boring in ice as lclaimed in claim 1, in which said series of straight' cutting edge sections are located generally on a convexly-shaped arc, the center of curvature of which is located inside o f the peripheral outline of the boring member. i. t

3. A device for boring in ice as claimed in claim l,

in which the curvedl trailing edge of the boring member includes a concavely curved rim section located opposite the portion of the cutting edge extending along the leading edge of the boring member. 4. A device for boring in-ice as claimed in claim l, in which two of said straight cutting edge sections meet at a point located at the lower end of the boring member and provide a boring point with a straight cutting edge section on its respective sides.

5; A device for boring in ice comprising a generally spoon-shaped boring member and means for etecting its rotation, said boring member having a curved trailing edge and `a sharpened leading edge and lower end portion providing a cutting edge for the boring member, said cutting edge being locatedv generally along a convexlyshaped arc the center of curvature of which is located inside of the peripheral outline of the boring member, and said curved trailing edge being dened in substantial part by a concave rim located opposite the portion of the cutting edge extending along the leading edge of the boring member and generally on an arc, the center of curvature of which is located outsideof the .peripheral outline of the boring member.

.6.,A device for boring in ice as claimed in claim 5, in which said concaverim extends from the sharpened cutting edge at the lower end of the boring member and inwardly therefrom to provide a recess in the trailing edge of the boring member.

y References Cited bythe Examiner UNITED ,STATES PATENTS CHARLES E. ocoNNELL, Primary Examiner. 

1. A DEVICE FOR BORING IN ICE COMPRISING A GENERALLY SPOON-SHAPED BORING MEMBER AND MEANS FOR EFFECTING ITS ROTATION, SAID BORING MEMBER HAVING A CURVED TRAILING EDGE AND A SHARPENED LEADING EDGE AND BORING END PROVIDING A CUTTING EDGE ON SAID BORING MEMBER, SAID CUTING EDGE BEING COMPRISED OF A PLURALITY OF STRAIGNT CUTTING EDGE SECTIONS ARRANGED IN SERIES WITH ADJACENT STRAIGHT 